MAINTE
ENANCE STRATEGY BASED ON RELIABILI Y IN COOPERATIVA CAFÉ TIMOR, EAST
THESIS
as Partial Fulfill of the Requirements Obtain the Bachelor of International
Industrial Engineering Degree
Arranged by:
NIZIA MARIA SARMENTO LOPES DA CRUZ Student number: 07 14 05284
INTERNATIONAL INDUSTRIAL ENGINEERING PROGRAM FACULTY OF INDUSTRIAL TECHNOLOGY
Dedicated to:
Pai, Mae
Gina, Ivo, Toni
v
ACKNOWLEDGEMENT
First, thanks for the blessing, spirit and
guidance of Jesus Christ, so the writer can finish this
thesis report entitled: MAINTENANCE STRATEGY BASED ON RELIABILITY (CASE STUDY IN COOPERATIVA CAFÉ TIMOR, EAST TIMOR) to fulfill one of the requirements to reach
bachelor degree of Industrial Engineering from
Universitas Atma Jaya Yogyakarta.
The successful completion of this thesis was also
able by splendid cooperation of everyone who support.
Therefore, in this opportunity, the writer would like
to say thank you to:
1. Mr. Ir. B. Kristyanto, M.Eng, Ph.D as the Dean of
Industrial Technology Faculty UAJY.
2. Mr. The Jin Ai, S.T., M.T., D.Eng, as the Chief of
Industrial Engineering Study Program FTI UAJY.
3. Mrs. Ririn Diar Astanti, D.Eng. as the Chief of
International Industrial Engineering Study Program
FTI UAJY.
4. Mr. Ag. Gatot Bintoro, S.T., M.T. as the advisor,
for the critical supports and suggestions during
this thesis process enabled the writer to
accomplish this thesis.
5. Mr. Josef Hernawan Nudu, S.T., M.T. as the
co-advisor, for the guidance and discussion during
the report constructing so that this report can be
vi
6. All the lectures and staffs of Industrial
Technology Faculty UAJY, for the knowledge and
help.
7. Mr. Bency Issac and Mr. Eusebio Dias Quintas for
letting the writer did the observation at
Cooperativa Café Timor (CCT).
8. Mr. Adelino do Carmo, as the co-advisor in
Cooperativa Café Timor (CCT), for the discussion
and inputs to this thesis.
9. My parents (Pai and Mae), Gina my elder sister,
Ivo my elder brother, Toni my younger brother, Tio
Pe. Iso, M’Nuno, Nita, and Nivio for all the
supports, prayers, loves, cares, and helps.
10. All my family, uncles, aunties, cousins, nieces,
and nephews, for all the prayers and supports.
11. Titina, Sela, Eka, Yani, Melly and kak Ima, all my
boarding house friends, for the friendship,
supports, helps, cares, and “stress therapy”.
12. Henny, Imelda, Rina, Marshela Pausha, Yosepina,
Ana and Ardi for the friendship.
13. My classmates, batch 2007, Randi, Danang, Phi,
Sherly, Melly, Phanie, Rachel, Panpan, Lilik,
Thomas, Alex (2006), and Chuck (2008) for such a
great friendship, supports and helps.
14. Other parties that could not say one by one that
have given much support to finish this thesis.
Last, the writer hopes that this report could bring
many advantages and new knowledge for the readers.
vii
TABLE OF CONTENT
Title Page... ... i
Statement of Work’s Originality... . ii
Approval... ... iii
Dedication... ... iv
Acknowledgement... ... v
Table of Content... ... vii
Figure List... ... ix
Table List... ... xi
Abstract... ... xii
CHAPTER 1 INTRODUCTION 1.1. Background... ... 1
1.2. Problem Statement... ... 4
1.3. Research Objective... ... 4
1.4. Scope of Research... ... 4
1.5. Research Methodology... ... 5
1.6. Report Outline... ... 9
CHAPTER 2 LITERATURE REVIEW 2.1. Previous Research... ... 12
2.2. Current Research... ... 14
CHAPTER 3 THEORY 3.1. Definition of Maintenance... ... 15
3.2. Types of Maintenance... ... 16
3.3. Reliability Function... ... 19
3.4. Failure Rate... ... 21
3.5. Time to Failure Distribution... ... 24
viii
3.7. Spare Part Inventory... ... 31
CHAPTER 4 COMPANY OVERVIEW AND DATA 4.1. Company Overview... ... 34
4.2. Data... ... 49
CHAPTER 5 ANALYSIS 5.1. Plant Reliability... ... 51
5.2. Failure Rate Test... ... 56
5.3. Optimum Interval Preventive Maintenance... .. 59
5.4. Spare Part Management... .... 63
CHAPTER 6 DISCUSSION... 66
CHAPTER 7 CONCLUSION AND RECOMMENDATION 7.1. Conclusion ... ... 72
7.2. Recommendation ... .... 72
REFFERENCE... 73
ix FIGURE LIST
Figure 1.1. Flow Chart of Research Methodology... 6
Figure 3.1. Reliability Curve... 20
Figure 3.2. Block Diagram of Reliability... 21
Figure 3.3. Failure Rate Curve... 23
Figure 3.4. Bath Tub Curve... 23
Figure 3.5. Form of Normal Distribution Curve... 24
Figure 3.6. Form of Weibull Distribution Curve... 25
Figure 3.7. Form of Gamma Distribution Curve... 26
Figure 3.8. Form of Uniform Distribution Curve... 27
Figure 3.9. Optimum Interval Preventive Maintenance 28 Figure 3.10. Interval of tp... 28
Figure 3.11. Elements of C(tp)... 30
Figure 3.12. Total Maintenance Cost per Time... 31
Figure 3.13. Classical EOQ Model... 32
Figure 4.1. Packaged Green Bean Coffee... 38
Figure 4.2. Packaged Roasted Coffee... 38
Figure 4.3. Packaged Ground Coffee... 38
Figure 4.4. Coffee Cherry... 44
Figure 4.5. Peeler Polisher Machine... 45
Figure 4.6. The Husks... 45
Figure 4.7. Dencimetric Table... 46
Figure 4.8. Grader Machine... 46
Figure 4.9. Women Sorting Using Sorting Conveyor.... 47
Figure 4.10. Women Sorting Manually... 47
Figure 4.11. Packaging of the Green Bean Coffee... 48
Figure 5.1. Plant Reliability System... 53
Figure 5.2. Machine and Plant Reliability System.... 56
Figure 5.3. Failure Rate Curve of Peeler Polisher... 58
Figure 5.5. C(tp) Curve of Peeler Polisher... 61
xi TABLE LISTS
Table 4.1. List of Machines... 49
Table 4.2. Data of Machines Downtime... 49
Table 4.3. Machines Working Hours Year 2007-2010.... 50
Table 4.4. Data of Machines... 50
Table 5.1. List of Machines, Functions... 52
Table 5.2. TTF Data of Peeler Polisher and Elevator1 54
Table 5.3. Parameter Based on Weibull Distribution.. 55
Table 5.4. Machine Reliability... 55
Table 5.5. Calculation of r(t) for Peeler Polisher.. 57
ABSTRACT
The purpose of this research is to determine the plant reliability and propose a proper maintenance strategy that can be applied in dry processing factory of Cooperativa Café Timor (CCT), East Timor. The analysis done such as: plant reliability, failure rate, optimum interval preventive maintenance, and spare part inventory.
The analysis of plant reliability is done to know the reliability of the plant and type of plant reliability system. The plant reliability is 0.99915 with series system. The analysis of failure rate is done with purpose to find a proper maintenance strategy for the potential subsystems (machines), such as peeler polisher and elevator 1. The analysis shows that the failure rate curve of peeler polisher and elevator 1 are increasing, therefore a proper maintenance strategy that can be applied is preventive maintenance. The analysis of optimum interval preventive maintenance is done to know the optimum interval time in doing the preventive maintenance. The optimum interval for peeler polisher and elevator are 1,229 Hours and 634 Hours respectively. The analysis of spare part inventory is done in order to ensure that the spare part is available when needed. This analysis is done using the Classical Economic Order Quantity (EOQ) Model, where the result shows that the order quantity of peeler polisher and elevator 1 are 7 and 9 Units respectively and reorder point are the same, which is 1 Unit.
